Long draft textile apron



Nov. 7, 1944.

H. M. BACON LONG DRAFT TEXTILE APRON Filed April 19, 1941 2 Sheets-Sheet1 Inventor HENRY M. BACON by a a Attorney,-

Nov. 7, 1944. H. M. BACON 2,362,340

LONG DRAFT TEXTILE APRON Filed April 19,1941 2 Sheets-Sheet 2 FTEB S U Un Inventor HENRYEQBACQN M WMJJ Attornz s Patented Nov. 7, 1944 LONGDRAFT TEXTILE APRON Henry M. Bacon, Dayton, Ohio, asslgnor to The DaytonRubber Manufacturing Company, Dayton, Ohio, a corporation of OhioApplication April 19, 1941, Serial No. 389,477

6 Claims.

My invention relates to textile draft aprons and their method ofmanufacture.

The invention has for its principal object the making of' an improveddraft apron having enhanced durability and long service life.

- Another object of this invention is to provide a draft apron made ofvulcanized rubberized fabric, or synthetic rubber composition, which, inaddition to possessing static free properties, high oil resistance, andlow stretchability with high recovery, has excellent resistance toabrasion.

Another object is to provide an improved draft apron which possessesproper coefilcient of friction at its surface for drafting the fibersand comprises an inner liner which is wear resistant.

Another object is to devise a draft apron and an improved method ofmaking it wherein a long, staple, substantially inextensible apron isprovided having an inner working surface of sufficient coeificient offriction and resistance to wear to prevent slippage during operation.

Still another object is to provide an improved draft apron made ofsynthetic rubber composition, or rubberized fabric, which is of aconstruction such as to improve the yarn quality and uniformity ofdrafting, as well as provide a lower cost apron of higher durability andone which does not tend to gather lint and contamination during use.

These and other objects and advantages will become apparent from thefollowing description taken in connection with the drawings.

For the purpose of illustrating my invention, the draft apron and methodof making it are shown as embodying a typical two apron drafting system.My invention, however, is not limited to this particular type ofdrafting system and is adapted for use in single orother type draftingsystems, as will be readily recognized by those skilled in the art.

In the drawings, the different steps in the method of making mydmproveddraft apron are diagrammatically illustrated.

Figure 1' illustrates diagrammatically a two apron draft system showingthe manner of using my improved draft apron;

Figure 2 illustrates the step of building up my apron on a mandrel inthe form of laminated layers, a portion being broken away and shown insection;

Figure 3 is a similar view showing the super imposing of the fiberdrafting outer surface layer onto the wear resistant inner body of theapron;

Figure 4 is a similar view illustrating the placing of the rag Wrappedor compressing material around'the outer surface of the built-up body ofthe apron preparatory to vulcanizing the same;v

Figure 5 is a diagrammatic view, partly in section, illustrating themanner of grinding or abrading the fiben working surface of the apron toproduce a proper coefficient of friction and uniform surface asrequired;

Figure 6 is a perspective view, partly in section, illustrating thefinished apron;

Figure 7 is an enlarged fragmentary sectional view taken on the linel-'l of Figure 6;

Figures 8, 9, 10, 11 and 12 are similar views as Figures 2, 3, 4 and 5and illustrate a modification wherein a modulated fabric layer isutilized as the inner wear resistant mat surface;

Figures 13, 14 and 15 are fragmentary detail view-s illustratingdifferent modulated fabric material which may be used to form the wearresistant inner surface of the apron made according to my invention;

Figure 16 is a perspective view, partly in section, illustrating thefinished apron made according to my invention and having a wearresistant inner surface;

Figure 17 is an enlarged fragmentary sectional view of the finished beltillustrating the flow of rubber or the resilient body portion of theapron into the spaced openings in the inner fabric layer.

During recent years the processing of staple fibers, both natural andartificial, such as cotton and rayon, has been greatly speeded up by thedevelopment of long draft, especially on spinning machines. Draft apronsare an essential part of the drafting system in the spinning of fibersand in order to provide for proper performance and to producesatisfactory yarn quality they must be manufactured to a very closetolerance. In addition, the draft aprons must possess static freeproperties, be highly resistant to attack by oil and have an abrasiveresistant inner working surface. Further, the apron must possess aninner working surface which has a minimum tendency to pick up fibers,such as lint and the-likeand exhibits a maximum resistance to thecutting action of the knurled roller. Moreover, the apron must have ahigh gripping force between its own surfaces and must not grow orstretch in service.

Referring to the drawings:

InFigure l the bottom rolls A, B and C are all driven, while the traprolls a, b and c are driven by friction from the bottom rolls which aredirectly therebeneath. The bottom rolls are generally made of steel andthe surfaces of the rolls A and C are ordinarily fluted, while thesurface of the roll B is knurled.

In operation, the fibers are pulled into the slow moving rolls A-a,which drive them at a uniformly slow rate to the interengaging draftprises "Stifiex" and contains fibers arranged parallel and extendingcircumferentially of the layer.

aprons D. The aprons are encased in rolls B-b which rotate somewhatfaster than the rolls A-a, resulting in effecting a minor drafting andparalleling of the fibers between the rolls A-a and 13-12. The fiberthen is drawn between the draft aprons D and delivered at a uniform ratethrough the rolls C-c. The latter rolls run much faster than the otherrolls resulting in still more drafting and paralleling of the fibers, so

that were it not for the holding and guiding effect of the aprons, thefiber web would break.

The draft aprons D are arranged to slide over The composition preferablyis compounded sixnilarly as in making the outer tire casing so as to beresistant to abrasion and temperature conditions under which the apronsare subjected in use.

' The gauge thickness of the layer It may be varied the metal holders 9:and y, as illustrated in Figure 1, which are held rigidly in positionand there is no pressure applied between the aprons at any point exceptat the contact of rolls 3-1).

It will thus be seen from Figure 1 that the lower apron is subjected torelatively heavy load. As shown, the lower apron is driven by the roll Band is drawn around the forward guide bar a: and must hold and deliverthe fibers while imparting positive movement to the upper engaging apronby frictional contact therewith. The power and motion of the entireapron assembly are transmitted by the roll B and to prevent slippage ofthis roll it is knurled, as is also the upper roll b. Under theseconditions, however, slippage of the apron and stoppage of the draftingoperation often result at which time the knurled roll B wears or cutsthrough the apron which necessitates its replacement.

Some other and more common reasons for slippage of the apron andstoppage of the drafting operation are as follows:

. (l) The choking up of the knurls on the rolls. This-happens when thespace between the sharp knurls becomes filled with foreign materialwhich eliminates the teeth-like gripping surface of the rolls.

The weights holding the top rolls in place become dislocated or loosewhich results in lowering the friction normally maintained by the properpositioning of the weights on the rolls.

(3) The choking up of the aprons. This occurs when the fibers breakbetween the rolls C-c and the :r-y guide members and the fiber webadheres to either of the aprons building up a sizable layer of fibers.Under this condition, the building up of the fiber layers in between theaprons finally brings about jamming of the aprons at :ci/. Choking ofthe apron also occurs when a lump of accumulated material inside theapron becomes wedged along the inner side of the apron as it passes overthe guide members a: or 11.

My improved draft apron is designed to eliminate the difficultiesencountered with ordinary draft aprons which have not been madeaccording to my invention. After a great deal of experimentation andresearch I have discovered that a draft apron which is made having ahighly abrasive resistant inner body portion substantially eliminatesthe above difliculties and a long wearing apron is provided.

One embodiment of my improved method of making draft aprons isillustrated in Figures 2 to 'I wherein the apron is built up in twostages. As illustrated, an inner friction resistant layer ID ofrubberized composition is laid on the mandrel I! so as to form afriction resistant layer of substantially uniform thickness. Thecomposition f r forming the inner layer In preferably com somewhatdepending upon the particular type and size of apron.

Over this layer of wear resistant rubberized fabric It is laid the outerfiber working cover layer It, containing fibers which are arrangedparallel and extend lengthwise of the apron as shown in Figures 6 and'7. This material may comprise any suitable resilient synthetic resin orrubber composition which is flexible and has a high coeflicient offriction. The composition, for example, may be of the improved staticfree, 011 resistant, synthetic rubber composition, as disclosed in theapplication of Joseph Rockoff, Serial No. 349,517. filed August 2, 1940.

After laying on this outer fiber working layer I over the inner wearresistant layer 10, a wrapped layer of fabric I6 is wound over the outersurface of the built-up apron under tension to compress the layerstogether. Thereafter the mandrel and built-up apron are placed in asuitable curing appartus and the material vulcanized to a unitary apronstructure.

Following the vulcanization the rag wrapper i5 is removed'and the outerworking surface of the layer I4 ground or skived oil? by application ofabrasive means I! so as to produce a finished apron having the pfoperfriction resistant outer fiber working surface. The outer fiber workingsurface of the apron is merely abraded off to remove protuberancesleaving the impression of the fabric, such as shown at 20, on thesurface to provide the proper coefiicient of friction at the surface'fordrafting the fiber material.

As illustrated in Figures 6 and 7, the finished aprong comprises alaminated body of unitary structure having an inner wear resistant layerID integrally united to the outer fiber working surface layer I4. Thisprovides a draft apron which has the desired fiber working surface layerand a strengthening inner surface portion. Such an apron resists thecutting action of the knurled rolls and does not have a tendency toaccumulate dust, lint and becoming clogged.

In Figures 8 to 17 there is illustrated a modified method of making theimproved draft apron of this invention. In this instance, the inner wearresistant layer comprises fabric, such as shown at 22. The fabric layer22 is positioned on the mandrel l2 and the fiber working surface coverportion I4 laid thereover and the material vulcanized similarly as setout above. After the apron body is vulcanized the surface is abraded, asshown in Figure 12, similarly as in Figure 5.

The fabric wear resistant layer 22 may be either straight or bias cut.The flexibility of the fabric is improved when out at a bias up toapproximately 45 degrees. Moreover, where desired, one or more plies maybe utilized or a combination of bias and straight out fabric. Theessential feature is the provision of a wear resistant inner layerhaving a high coefficient of friction for the fiber draft apron. Fabrichas a high resistance to knurl cutting and various types of fabric withor without bonding or impregnated abrasive resistant material may beused.

Preferably the fabric inner layer material 22 is provided with spacedslots, as illustrated in Figures 13, 14 and 15. As shown in Figure 13,

the fabric layer is provided-with spaced slots 25 which are arranged inrows and spaced parallel to the longitudinal axis of the draft apron. If

desired, the slots 25 may be staggered, as illustrated in Figure 14.These slots extend only through the fabric and during vulcanization ofthe inner layer to the outer fiber working cover M the rubberizedmaterial is pressed through the slots and provides an inner workingsurface having alternate fabric and rubber composition, such as shown at21 and 28, respectively, in Figure 17. In this way, the apron isprovided with an inner wear resistant mat surface similar to a tiretread and has enhanced gripping action on the cured roll surface whileat the same time resisting wear and slippage of the rolls.

The belts disclosed in Figures 13 to 17 are provided with the sameworking cover as shown in Figures 1 to 7 and this working cover may beprovided with fibers arranged parallel and extending circumferentiallyof the layer as stated in connection with the description of Figures 1to 7. These fibers are shown in Figure 16 as constituting part of thecover portion N.

In Figure the spaced slots 25 in the inner fabric layer are arranged atan angle to the longitudinal axis of the draft apron so as to exert acleaning action during operation to keep the knurls on the rolls freefrom foreign material. The arrangement of the slots, as will be observedwhen the apron is moved in the direction of the arrow shown in Figure15, will tend to carry foreign material to the edge of the apronpreventing its accumulation.

The outer fiber working surface 20 comprises the imprinting of thejacket wrapper which is wound around the material before vulcanizationand which imprint is modified by grinding or abrading so as to produce afairly even surface, as illustrated in Figure 12, similarly as in theapron illustrated in Figures 6 and 7.

It will be understood that other methods of combining the desired fiberprocessing surfaces with a long wearing resilient, friction innersurface layer may be used which will provide a long draft apron havingboth a fiber working surface and an integrally united inner wearresistant layer.

It will be further understood that this invention is not limited to thespecific method steps and particular composition of the fiber workinglayer and inner wear resistant portion, as illustrated, but may bemodified tosuit different conditions and uses as required within thescope of this invention and the appended claims.

Having thus fully described my invention, what I claim as new and desireto secure by Letters Patent is:

1. As an article of manufacture, a draft apron comprising an outerresilient fiber working surface composition layer and an inner surfaceadapted for contacting the draft roll, said inner surface comprising afabric layer provided with a plurality of relatively large spacedopenings cut through the fabric distinct from and forming no part of butlarger in area than the interstices of said fabric layer through whichportions of the composition forming the working surface layer protrude,said protrusions being of substantial size and adapted to provide atread having enhanced gripping action.

2. As an article of manufacture, a draft apron according to claim 1wherein the fiber working surface layer comprises a vulcanized resilientcomposition reinforced with fine textile fibers I lying substantiallyparallel to each other,

3. As an article of manufacture, a draft apron comprising an outersurface layer of rubber composition and an inner roll contacting surfacelayer of reinforced fabric construction, said fabric being provided witha plurality of relatively large spaced openings cut-through the fabricdistinct from and forming no part of but larger in area than theinterstices of said fabric layer through which portions of the rubbercomposition forming the outer surface layer protrude, said protrusionsbeing of substantial size and adapted to provide a tread surface havingenhanced gripping action.

4. As an article of manufacture, a draft apron according to claim 3wherein the outer surface layer comprises a vulcanized resilientcomposition reinforced with fine textile fibers lying substantiallyparallel to each other.

5. As an article of manufacture, a draft apron consisting of an integralbody having an outer fiber working resilient composition surface and aninner wear resistant gripping surface, said gripping surface comprisinga fabric layer provided with a plurality of relatively large spacedopenings cut through the fabric distinct from and forming no part of butlarger in area than the interstices of said fabric layer arranged at anangle to the longitudinal axis of said apron, said apron having portionsof the composition forming the outer fiber working surface protrudingthrough said openings forming protrusions of relatively large size.

6. As an article of manufacture, a draft apron according to claim 5wherein the outer fiber work-

